An electrode mixture is used for an electrode in a nonaqueous electrolyte secondary battery or the like, and a sodium secondary battery is studied as the nonaqueous electrolyte secondary battery. A sodium-containing compound constituting the sodium secondary battery is abundant in the amount of resources and also is an inexpensive material, and therefore, by putting this into practical use, it is expected that large-scale power sources can be supplied in a large amount.
The sodium secondary battery usually has at least one pair of electrodes including a positive electrode composed of a positive electrode containing sodium-containing compound that is doped and undoped with a sodium ion as a positive electrode active material and a negative electrode containing a negative electrode active material that is doped and undoped with a sodium ion, and has an electrolyte.
The electrode contains a current collector and an electrode mixture carried on the current collector. In order to carry the electrode mixture on the current collector, an electrode mixture paste containing the electrode mixture and an organic solvent is applied onto the current collector and dried. As the electrode mixture paste, there has been studied, for example, a material obtained by mixing and kneading an electrode active material such as a positive electrode active material or a negative electrode active material, an electroconductive material, a binder and an organic solvent (Non-Patent Document 1).